It doesn't really have anything to do with people spending more on records these days than on films. It's about the use of particular songs , or any piece of work for that matter, that were released that are used in other productions. (That is the meaning of royalties).
Definition of 'royalties'
"A sum of money paid to a patentee for the use of a patent or to an author or composer for each copy of a book sold or for each public performance of a work."
Nobody here could say whether it's true unless they did significant research, but I would hazard a guess and say yes, it is true, because even in very recent movies, they use other songs that artists have created.
To clarify further.
Films of the past are not as regularly used in this day and age, while the music, created in the same era is.
Frank Sinatra for instance, or Michael Jackson, or Elvis Presley.